Process for producing acetic acid.



UNITED STATES PATENT OFFICE.

NATHAN G-R'O'NSTE IN, O'F FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOR TO THE CORPORATION OF CHEMISCHE FABRIK GRIESHEIM-ELEKTRON, OF FRANKFORT-ON- THE-MAIN, GERMANY.

PROCESS FOR PRODUCING ACETIC A011 No Drawing.

To all whom z't may concern":

Be it known that I, NATHAN GRt'iNs'rEIN, a citizen of the Russian Empire, and resident of Frankfort-on-the-Main, Germany, have invented new and useful Improvements of Processes for Producing Acetic Acid, of which the following is a specification.

Hitherto the technical production of acetic acid from acetylene was performed in such a manner that the acetaldehyde obtained the hydration of acetylene was isolated arate operation. The production of acetic acid from aldehyde was performed in such manner, that for instance pure'acetaldehyde was treated with oxygen or air in the presence of a great deal of acetic acid, monochloracetic acid or the like, whereby the oxidation could be accelerated by the additionof oxygen carrying bodies, as for instance ferrous-ferric-oxid, vanadium pentoxid, vuranic oxid and the like. Now I have discovered that the process of manufacturing acetic acid from acetylene may be simplified and that the expensive separation and purification of the acetaldehyde may be avoided by directly producing the acetic acid from acetylene. This may be doneby treating acetic acid, containing water, and to' which mercury salts have been added, withacetylene and oxygen, whereby the obtained acetaldehyde is converted into acetic acid in the same solution. Instead of acetic acid which is a water-soluble aliphatic acid monochloracetic acid and some other organic acids may be used as reaction-liquid; but in this case the obtained acetic acid must be separated by fractional distillation from monochlor'acetic acid or the like.

The hydration of the acetylene is accelerated by the addition of small quantities of sulfuric acid, phosphoric acid or the like, while the oxidation of the acetaldehyde is very favorably infiuenced'b'y adding oxygen carriers, such as the oxide ofiron, vanadium pentoxid and the like.

The process may for out in such a manner,

instance be carried that 1nto an acetic acid, containing water, and to which mer-.

. 'curic or mercurous salts have been added,

acetylene and oxygen are alternately introduced. The amount of oxygen must correspond to that necessary for the format1on Specification of Letters Patent.

Application filed June 4, 1914. Serial No. 842,949.

added 10 parts mercuric oxid; one part suI-- Patented Mar. *7, 1916.

of acetic acid from acetaldehyde by oxidation; thereby the'acetic acid is obtained in a smooth manner. Preferably the acetylene is introduced during a short time only and then the produced aldehyde is at once oxidized by means of oxygen. The simultaneous introduction of both, acetylene and oxygen, is likewise possible, but it is to be remarked, that the absorption of the gases is thereby retarded. Preferably the process 1s carried out in a concentrated'acid, as with-a higher content of water the oxidation of the acetaldehyde to acetic acid is likewise retarded. As soon as a sufficient quantity of acetic acid has been formed in the apparatus the clear solution is drawn ofi, whereby an acetic acid of high percentage is obtained, which contains but the water, which has been added in excess. The acid may be purified by distillation or by any other known method.

The present invention shows the great advantage, that the acetic acid can be produced in one operation from acetylene, water and oxygen, so that the expensive separation of the acetaldehyde is avoided, which involves unavoidable loss. When using concentrated acetic acid as reaction-liquid an acetic acid of high percentage is obtained.

It is very remarkable, that with this process, also when using diluted acetic acid, the

acetaldehyde is stilloxidized to acetic acid by the oxygen, while pure acetaldehydegives no reaction with oxygen when brought together in an acetic acid of thesame concentration. Besides the processis a very favorable one due to the fact, that the mercury salt, ner, is reduced but very slowly mercury, so that only a small quantity of mercury is used.

The following example illustrates the manner, in which the invention may be carried out, but Idonot limit myself there To 200 parts of acetic acid 90% are furic acid or 2 parts phosphoric acid may or may not be added thereto. Acetylene is introduced while strongly agitating during some time, say one hour; the temperature being kept at about 7090C. Then the amount of oxygen, which is necessary for oxidizing the formed acetaldehyde to acetic which acts in a catalytical mam to metallic acid is introduced. In the same manner acetylene and oxygen are alternately introduced, while the water, which has been consumed for the formation of aldehyde is replaced continuously or periodically.

inated by passing a powerful stream of' oxygen through the apparatus or by any other suitable means- 'The produced acetic acid is drawn oil from time to time, while the process is continued. By the above process an acetic acidof-about 95% is obtained with a yield of 90100% of the theory. By distillation pure glacial acetic acid may be obtained therefrom. It is to'be remarked,

that the mercury salt, especially when the process is carried out on a larger scale, is consumedin a remarkably small degree, so

that fresh catalytic substances need not be, added but very rarely; In case a diluted acetic acid. is 'used as reaction liquid, the concentration 1 thereof will gradually" rise, as Water is consumed by the formation of aldehyde. Therefore while starting from diluted acetic acid one can obtain a concentrated acid or it is possible to vary the conacetic acid is separated from'the mixture by fractional distillation. Instead of mercentration according to the added water. lVhen instead of "aceticfacid monochloracetic acid, or another suitable organic acid is used as reaction liquid, the produced curic or mercurous oxid there maybe used other mercuric or mercurous compounds, as for instance mercuric or mercurous sulfate, phosphate or the like. Or there may be used mixtures of 'such salts or compounds. W hen mercuric sulfate or phosphate is used, it is not more necessary to add free sulfuric acid, phosphoric acid or the-like. The mercury which has been-used as a catalytical body during the process may be regenerated and introduced once more in the process. The fresh contact bodies may be added continuously or periodically.

. When in the claims I speak of acetic acid, I mean by that expression to include also a substituted acetic acid, particularly a chloracetic acid.

Now what I claim and desire to secure by Letters Patent is the following:

1. The process'of producing acetic acid, which consists in allowing to react on each other acetylene," water and oxygen in the presence of acetic acid anda mercury com which consists inallowing to react on each other acetylene, water and oxygen in the presence ofacetic acid, a mercury compound and an inorganic acid substantially as described.

4. Theprocess of producing acetic acid, which consists in allowing to react on each other acetylene, water and oxygen in the presence of acetic acid, a mercury compound and phosphoric acid substantially as described. I

5. The process of producing acetic acid, which consists in introducing acetylene and oxygen into acetic acid in the presence of water and a mercury compound substantially as described.

6.- The process of producing acetic acid,

which consists in introducing acetyleneand oxygen alternately into acetic acid in the presence of water and a mercury compound.

substantially as described.

7. The process of producing acetic acid, which consists in introducing acetylene and oxygen alternately into .acetic acid in the presence of water, a mercury compound and an oxygen carrier substantially as described.

8. The process of' producing acetic acid, which consists inintroducing acetylene and oxygen alternately into acetic acidin the oxygen and water in the presence of an aliphatic-1 acid, a mercury compound and an accelerating-agent.

12. The manufacture of acetic acid by allowing to react on each other acetylene,

"oxygen and water in the presence of an aliphatic acid, a mercury compound and an oxygen carrier. 1

13. The manufacture of acetic acid by allowing to react on each other acetylene, oxygen and water in the presence of an aliphatic acid, a mercury compound and an inorganic acid.

14:. The manufacture of acetic acid by in troducing acetylene and, oxygen into an aliphatic acid in the presence of water and a mercury compound.

15. The manufacture of acetic acid by introducing acetylene and oxygen alterallowing to react on each other acetylene,

nately into an aliphatic acid in the presence 1 of water and a mercury compound. 7

16. The manufacture of acetic acid by introducing acetylene and oxygen into an aliphatic acid in the presence of Water, a mercury compound, and an accelerating agent.

17. The process of producing acetic acid, which consists in allowing to react on each other acetylene, water and oxygen in the presence of acetic acid, a mercury compound and an accelerating agent substantially as described.

1.8. The process of producing acetic acid, which consists in introducing'acetylene and oxygen alternately into acetic acid in the presence of water, a mercury compound and an accelerating agent substantially as described.

19. The manufacture of acetic acid by allowing toreact on each other acetylene, oxygen and water in the presence of a watersoluble aliphatic acid and a mercury compound.

20. The manufacture of acetic acid by allowing to react on each other acetylene, oxygen and water in the presence of a watersoluble aliphatic acid, a mercury compound and an inorganic acid.

21. The manufacture of acetic acid by introducing acetylene and oxygen into a Watersoluble aliphatic acid in the presence of w'ater and a mercury compound.

22. The manufacture of acetic acid by introducing acetylene and oxygen alternately into a water-soluble aliphatic acid in the presence of water and a mercury compound.

That I claim the foregoing as my invention, I have signed my name in presence of two Witnesses, this twenty-seventh day of May 1914.

. NATHAN GRUNSTEIN. Witnesses:

JEAN GRUND, CARL GRUND. 

